When consumers launder fabrics, they desire not only excellence in fabric cleaning, they also seek to impart superior fabric care benefits. Such desired fabric care benefits can be exemplified by one or more of: superior garment appearance; excellent tactile characteristics, such as fabric feel; fabric softness; reduction, removal or prevention of creases or wrinkles in garments; color care; superior ease of ironing; garment shape retention and/or shape recovery; and fabric elasticity. Compositions which can provide fabric care benefits during laundering operations are known, for example in form of rinse-added fabric softening compositions. Compositions which can provide both cleaning and fabric care benefits, e.g., fabric softening benefits, at the same time, are also known, for example in the form of “2-in-1” compositions and/or “softening through the wash” compositions.
Fabric treatment compositions for use in laundering operations have been known for many years. They are available in solid form, e.g. in form of granules, in form of compressed tablets, and in liquid forms, e.g. as liquid compositions. Current liquid fabric treatment compositions comprise a fabric care ingredient, which is typically a cationic compound. More typically the cationic fabric care ingredient is a cationic silicone polymer comprising one or more polysiloxane units and one or more quaternary nitrogen units. WO 02/18 528 (P&G, published Mar. 07, 2002) describes fabric care compositions comprising a cationic silicone fabric care component and a nonionic surfactant.
Cationic fabric care materials such as the silicone-based quaternary nitrogen materials just described are generally insoluble in liquid fabric treatment compositions. Accordingly they are generally found in such liquid products in the form of emulsions or dispersions. These liquid compositions will thus frequently contain, in addition to the fabric care agent, a structuring system comprising an emulsified structuring agent. Such a structuring system serves to stabilize the cationic fabric care materials within the liquid fabric treatment compositions and to provide such liquid compositions with suitable rheological characteristics.
The structuring systems for liquid fabric care compositions, typically in the form of emulsified, crystal-forming stabilizing agents, are frequently prepared as a premix and then added to the liquid products which contain the cationic fabric care ingredients. In preparing such emulsified premixes of structuring agent, care is generally taken not to employ any emulsifiers which would be incompatible with the cationic fabric care materials in the fabric care compositions with which the emulsified structuring system will be combined. Accordingly, such structuring systems will generally comprise a mixture of a structuring agent and nonionic, and/or amphoteric emulsifiers.
It has been found that addition of small amounts of anionic emulsifiers to structuring systems for cationic fabric care compositions can greatly enhance the ability of the structuring system to provide structured liquid fabric care compositions of especially desirable stability and rheology. However, it has also been observed that the fabric care performance of the silicone-based cationic active decreases dramatically with the addition of a structuring system containing even very low levels of anionic emulsifier. Without being bound by theory, it is believed that the decrease in the fabric care performance occurs due to an interaction of the anionic emulsifier with the cationic fabric care ingredient, e.g. via ion-ion-pair formation of the anionic emulsifier of the structuring system and of the cationic fabric care ingredient.
The present invention addresses this technical problem and provides a solution to overcome this problem. Accordingly, it is an object of the present invention to provide fabric care compositions showing improved stability and rheology, in terms of good emulsification, structuring, and viscosity, and still provide superior fabric care.
It has been surprisingly found that the addition to the compositions herein of a cationic scavenging agent for the anionic emulsifier of the structuring system solves the problem set forth hereinabove. Without being bound by theory, it is believed that the addition of a cationic scavenging agent prevents the interaction of the anionic emulsifier of the structuring system with the silicone based cationic fabric care ingredient.